Sewer lines are cleaned using high pressure water connected to a cleaning head. The cleaning head is inserted into the sewer line at a downstream manhole. Once inserted, the cleaning head is propelled up-stream through the sewer line by the high pressure water. The debris dislodged by the high pressure water is washed downstream and collects in the downstream manhole. Once in the downstream manhole, the debris (sewage slurry) is separated from the water using a sewage slurry separation system. The water separated from the sewage slurry is returned to the sewer line and the remaining sewage slurry is retained for later disposal.